Preservation
Restoration & Conservation
Original material carries information that cannot be recovered once removed. This section separates three activities that are often confused, and states plainly where amateur work destroys value and where it is reasonable.
Definitions
Conservation, restoration, repair
Conservation
Stabilising an object and preventing further deterioration while changing as little as possible. Corrosion is arrested, not polished away; surfaces are cleaned, not refinished.
Restoration
Returning an object toward a previous state, which necessarily involves interpretation and loss. Every restoration decision should be documented and, ideally, reversible.
Repair
Making the object work again. Legitimate and often necessary — but a repair that discards original parts is a permanent trade of evidence for function.
Practice
Operations and their risks
Reasonable for an informed owner
- Gentle external cleaning of a case with appropriate, non-abrasive materials
- Correct storage: stable humidity, away from heat, movements unwound for long storage
- Photographic documentation before any intervention
- Recording service history with dates and named workshops
- Sourcing a correct replacement crystal rather than an approximate fit
Professional work only
- Full disassembly, cleaning and lubrication of a movement
- Mainspring replacement, especially in fusee and spring-barrel clocks
- Balance staff, pivot and jewelling work
- Escapement adjustment and rate regulation
- Dial conservation — refinishing a dial is usually irreversible value loss
- Rust treatment on steel components
A wound mainspring stores substantial energy. Attempting escapement or barrel work without training risks injury to you and permanent damage to the movement.
Principle
When to leave it alone
A watch that has not run for fifty years is not urgent. Running a dirty movement causes wear with every oscillation, so the correct first step is usually to stop — not to wind it repeatedly. Similarly, an original dial with hairlines is more informative and more desirable than a freshly repainted one, and a case with honest wear tells a story that polishing erases.
Where sources disagree on best practice — and they do, particularly on dial cleaning — this site states the disagreement rather than presenting one school as settled.